amazon-kinesis-client/amazon-kinesis-client
Aravinda Kidambi Srinivasan 651bf4d28c Fix a race condition between ShardConsumer shutdown and initialization
When Kinesis shards have no data, there can be a race condition where
the shard-end record processing from RecordProcessorThread
interleaves with Scheduler performing initialization.
This leads to ShardConsumer making incorrect state transition
during initialization (moves from PROCESSING -> SHUTTING_DOWN) state
and during shutdown handling it moves from SHUTTING_DOWN -> SHUTDOWN_COMPLETE
without running the ShutdownTask.

This can cause the ShardConsumer to not perform proper shutdown
processing that is required for a child shard processing
to be unblocked. So the child shard could be blocked forever unless the
lease for the parent shard moves to a new worker and that worker does
not run into the race condition.

This patch fixes the race condition as follows:

The intializationComplete invocation is not needed after
needsInitialization has been set to false. Because initializationComplete
is mean to perform initialization in an async manner, but once
its done, the async task is a no-op in happy-path, but it can
perform incorrect state transition during a race condition.
2024-04-29 10:42:26 -07:00
..
src Fix a race condition between ShardConsumer shutdown and initialization 2024-04-29 10:42:26 -07:00
pom.xml Create script to check for backwards compatibility (#1316) 2024-04-19 14:01:04 -07:00